Production and Characterization of Rodent (rat and mouse) Monoclonal Antibodies to HTLV III/LAV Mouse and rat monoclonal antibodies will be produced against HTLV-III, the human retrovirus associated with AIDS and a spectrum of related syndromes. The contractor will employ intact HTLV-III virions coupled to KLH as immunogen, and use a sensitive ELISA assay, based on purified HTLV-III as the antigen in a primary screening procedure. Immunoprecipitation, Western Blotting and cellular immunofluorescence will be used to characterize stable, immunoglobulin secreting, ELISA reactive subclones. Antibody binding constants will be assessed by standard procedures. Fine mapping of antibody specificity as it correlates with biological effects will be examined in the context of separate Phase II funding. Preliminary studies have demonstrated the feasibility of the approach proposed, resulting in the generation of both mouse and rat monoclonal antibodies to HTLV-III determined antigens. The successful completion of this project will involve the establishment of a complete panel of rat and mouse monoclonal antibodies with high avidity against epitopes which may be weakly immunogenic or silent in the normal host.